Finally stripped down my motor for a rebuild. What should I do about the jet valves?
1. Keep them
2. Get a Jet Valve elimination kit
3. Have the holes welded up
4. Get a non Jet Valve head
Any good advice is appreciated
You shouldn't have any problems finding a non-jet valve head in NZ, in fact I'd say a jet valved head is much more uncommon here than the non-jet valved head because I've never seen one except in pictures.
Are there likely to be any problems with running a FWD or non turbo head? I was told that some later single cam motors have roller rockers. Will one of these heads require any changes and would it be worth getting one?
Im going to jave to say option 1. Mitsubishi put them there for a reason. The car withought them would run real lean. The jet valves put in a rich af mixture back into the cylinder head. So i would say keep them.
Garrett G$
1986 Dodge Conquest Le Turbo
1994 Ford Probe-Daily Driver
They are an emission control device that can lead to cracking in the head in modded motors... And not all heads are Jet Valve so you dont have to have them.
-JA Starion with JD bits , Forged engine, Heaps of mods (parked up)
-BFII XR6 Turbo Ute , Here comes 400hp for 2k :p
-77 Mazda 323 drag car. 13bt rotary project.
I was under the impression that an ultra lean mixture is injected through the jet valves? I've never had a look at them but I assume that with them blocked up the air/fuel mix will just go through the main inlet valve therefore causing no affect to the air/fuel ratio.
The roller rocker information turns out to be incorrect... they come on a 4g37 1.8 SOHC, completly different motor :(.
I put blanking plugs in my head. It dosent go yet however, so no idea if it'll crack or not.
FWD and SOHC heads are the same, the turbo ones have a big T embossed on the back of them, but ive never noticied any difference other than that between the turbo and non turbo ones.
if the head is off just have a local head repair shop weld up the
jet valve openings. no harm done as i have done this. i have no hot spot to worry about nor emissions. if you have to worry bout emissions.
dont do this, unless your running a hot ignition, some sort of fuel controler
those that can follow keep up,those who cant leave them